磁共振成像阴性的全面强直阵挛性癫痫发作间期SPECT研究

Interictal SPECT in Generalized Tonic Clonic Seizure with Normal MRI Findings

目的:研究MRI阴性的全面强直阵挛性发作癫痫(GTCS)患者在发作间期脑血流灌注特征。材料和方法:对60例MRI阴性的GTCS患者进行发作间期99mTc-ECD(双半胱乙脂)-SPECT脑血流灌注显像,10例年龄匹配的健康人作对照,计算感兴趣区(ROI)的不对称指数(％AI)并进行定量分析。将SPECT分析结果与患者的临床表现与EEG相比较。结果:60例MRI阴性的GTCS患者中29例表现为一侧丘脑、基底节区低灌注,其中4例为丘脑伴同侧颞叶低灌注,1例丘脑伴同侧颞叶及小脑低灌注,3例丘脑伴同侧枕叶低灌注,另有5例仅表现为一侧顶叶或颞叶低灌注,异常率为56.7％;而26例(43.3％)血流灌注无异常表现。脑血流灌注异常与正常的患者在性别、年龄、发病年龄、病程及EEG异常率方面无显著性差异(P>0.05),而平均发作频率和总发作次数则具有显著性差异(P<0.05)。患者组和正常对照组在丘脑和基底节区的％AI存在显著性差异(P<0.05)。结论:①相当一部分MRI阴性GTCS患者存在发作间期脑血流灌注异常;②MRI阴性GTCS患者的脑血流异常灌注区主要分布在丘脑及基底节区而非皮质;③低灌注脑区可能是亚临床病灶或是癫痫反复发作所致的脑损伤区,这部分患者对药物治疗反应及预后不佳。

Purpose: To study the cerebral perfusion in generalized tonic clonic zeizure(GTCS) with normal MRI findings using interictal Tc-99m ethyl cysteinate dimmer(ECD) SPECT. Materials and Methods: Tc-99m ECD SPECT was performed in 60 GTCS patients during interictal phase and 10 age - matched healthy persons. SPECT was semi - quantitatively analyzed using a region of interest analysis (ROI), and an asymmetry index (AI) was measured from the ratio of two symmetrical regions of interest. The SPECT findings were compared with seizure frequency and EEG. Results: Interictal SPECT abnormalities were observed in 34 out of 60 patients(56.7% ), including thalamic and(or) basal ganglia hypoperfusion in 29 cases(4 of them companied with ipsilateral temporal hypoperfusion, 3 of them companied with ipsilateral occipital hypoperfusion, 1 of them companied with ipsilateral temporal and cerebellum hypoperfusion) , and parietal or temporal hypoperfusion in 5 cases.There was a significant difference in frequency of seizure between patients with abnormal SPECT findings and those without abnormal SPECT findings, while there was no dramatic difference in age, sex, age at onset, duration of epilepsy and EEG. Conclusion: (1)Part of GTCS with normal MRI findings can be found regional hypoperfusion by interictal SPECT.(2)The abnormal SPECT showed in GTCS with normal MRI is thalamic and basal ganglia hypoperfusion rather than cortex abnormality. (3)The interictal hypoperfusion in GTCS may indicate a subclinical focus or injured cerebral zone caused by long - time epileptic seizures, which may stands for refractory to treatment by AEDs and a poor prognosis.